Heating and ventilating apparatus



Aug. 9, 1932. 1. c. MILES 1,870,251

HEATING AND VENTILATING APPARATUS Filed Aug. 14, 1929 2 sheets-sheet 1 @gy-Mg wm (hlm/y dse Knees-#dimly r Aug. 9, 1932. J. c. MILES 1,870,261

HEATING AND VENTILATING APPARATUS v Filed Aug. 14, 1929 2 Sheets-Sheet 2 FIC-.L4

Patented Aug. 9, 1932 UNITED STATES JAMES C. MILES, OF CLEVELAND, OHIO HEATING ANI) VENTILATING APPARATUS Application filed August 14, 1929. Serial No. 385,723.

This invention relates to heating and ventilating apparatus and particularly to that type which is intended for use in the operation o-f a hot air heating furnace. To secure uniform l distribution of air from the furnace through the various delivery pipes and thence to the rooms, it is advantageous to use a fan located in the air intake conduit of the furnace, and to operate the fan at certain intervals. Ordinarily under the gravity system, a predetermined area of inlet opening is required to maintain an adequate supply of air in the heating chamber. Therefore, if a fan is placed in the inlet opening, provision must be made to restrict the opening, in order that when the fan is in operation all the air entering the chamber will be forced thereinto through the fan opening. Accordingly to prevent the furnace from burning out, provision must also be made for an adequate area of opening when the fan is not in operation. The principal obj ect of the present invention is to provide an apparatus adapted to be used in connection with the operation of a hot air heating furnace to change the furnace from a gavity system to a forced air system when so desired.

An additional object is to so construct the apparatus that it may be readily installed 1n existing furnaces and may rapidly be actuated to effect the change from one system to another.

Another object of the present invention is to provide an apparatus which, when installed on the furnace may readily be controlled from a remote point.r

A further obj ect is to provide an apparatus which. when not in operation permits asuilicient area. of opening for satisfactory operation of the furnace under the gravity system.

A further object is to provide an apparatus which will restrict the area of the inlet opening to the furnace to that of the fan opening,

when the fan is in operation, thereby causing all of the air going into the furnace chamber to i'iow through the fan opening.

A further object is to provide an apparatus wherein the operation of the fan will cause the inlet opening to the furnace chamber to be restricted to the fan opening when the fan is in operation.

This invention is adapted for use in connection with furnaces having an air inlet passageway opening into the furnace room, and is also adapted to be used in connection with the operation of a furnace wherein the air inlet passageway is connected to a riser through which air enters the heat chamber of the furnace from the rooms.

In the drawings, Fig. l is a side elevation showing a portion of a hot air heating furnace embodying my invention; Fig. 2 is an end elevation of an apparatus embodying my invention, the motor being brokeny away; Fig. 3 is a horizontal section taken on a plane indicated by the line 3-3 in Fig. 2; Fig. 4 is an end elevation similar to that shown in Fig. 2 with some of the parts in a different position; Fig. 5 is an enlarged sectional view taken 70 along the lines 5-5 of Fig. 2; Fig. 6 is an enlarged sectional view taken along the line 6-6 in Fig. 2; Figs. 7 to l1 inclusiveare enlarged rear elevations illustrating the portion of the main operating bar and its correspending position with respect to the controlling pin, these sections being taken at different stages of operation of the bar.

The hot air heating furnace, as illustrated, comprises a heat chamber l0 having an air 80 inlet conduit 1l leading thereto. As shown, this conduit opens directly into the room in which the furnace is located. The cross sectional area of the conduit is such that a sulficient amount of air may enter the heat chamber to provide adequate hea-t under the gravity system. A fan indicated at l5 is arranged to be driven by an electric motor 16 and is used for changing the system of gravity to forced air type.

In the preferred embodiment, the fan is mounted adjacent the opening 18 in a frame 19. As the fan opening is considerably smaller than the cross sectional area of the conduit, provision is made for utilizing movable dampers which, when open,allow sufhcient area for the movement of air through the conduit under the gravity system. Such .dampers are indicated at 2O and 2l and may 100 a lever 24 having a slot 26 coacting with a pin 27 rigidly mounted on the universal bar. Accordingly, it may be seen that when the bar is moved to the left in its extreme position the dampers 20 and 2l will be in Van open position, as illustrated by Figs. 2 and 3. However, vwhen the bar has been moved to the right to its extreme position, the dampers 20 and 21' will be closed, as illustrated in Fig. 4.

To effect, the operation of thel control bar 25 I prefer to mount the latter in bearing members 30 which are rigidly secured to the frame 19. Mounted on the motor shaft is a toothed pinion 31 which is adapted to coact With a rack portion of the bar 25 having teeth 32. It will be noted that there are only a comp aratively small number of teeth on the bar and that there is a cut-awayportion of the bar immediately 'to the left of the last tooth. Accordingly, When the motor is started it will immediately tend to move the bar towards the right (see Fig. 2). This movement will partially close the dampers 20 and 21. However, when the dalnpers have been partially closed by reason of theV action of the rack portion of the bar 25 and pinion 31, sufficient air presure will be built up in the conduit by the operation of the fan to complete the closing and by this 'time the pinion 31 will have reached the last tooth towards the left (in Fig. 2) on kthe bar 25. The final movement of the dampers causes the bar to'move to the extreme right-hand positionwhere the pinion 31 is free to rotate idly by reason of the cut# away portion 33 of the bar 25. The air pressure in `the conduit is sutlicient to retain the dampers 20 and 21 in their closed position and to overcome the force of va suitable spring 35, which serves to retract the ydampers to normal position, `as will be hereinafter more fully described.

When the motor is stopped, the air pressure in the conduit 11 decreases to a point Where it will be overcome by the action of a spring 35. One end of the spring is secured to a suitable bracket 36 mounted on the frame 19, and the other end is secured to the bar 25. Thus the spring will normally return the bar to its original position whereinthe dampers 20 and 21 are opened by movement of the bar (to the leftvas illustrated in Fig. 2).

To return the bar 25 so that the Vteeth 32 will'notcontact with the teeth 31 of the motor pinion, I preferk to mount the bar 25 in its bearings 30'in such manner that it may not only be slid laterally to open and close the dampers but also may have a vertical movement sufficient to cause the teeth 32 of the bar to be disconnected from the teeth 31 of the motor pinion. To this end, I mount pins 40 on the frame 19 adjacent its ends as is illusi their respective guideways are best illustrated 1 in Figs. 7 to 11 inclusive. Fig. 7, for example, illustrates the position of a pin during the timev at which the damper is open and the motor is off. At such time, the spring 35 holds the bar in the extreme right hand position. I As the motor starts however, the initial turning movement of the fan shaft moves the bar against the tension of the spring, and thereby forces it to the position shown in Fig. 8 and moves the dalnpers toward the closed position. y The relationship between the teeth on the rack and those on the pinion is such that the cam at the end of the guideway' will engage the pin and thereby start the lowering operation of the bar against the tension of the spring. The teeth are disengaged however, before the pin moves the entire length of the cam, but the momentum of the dampers incident to the closing operation coupled with the air pressure incident to the operation rof the fan Aholds the dampers closed and thereby maintains the bar andpin in the relative position shown in Fig. 9, so long as the fan is in operation.

As soon as the fan is stopped however, the air pressure is diminished and the spring acts upon the bar to null it tothe position shown in Fig. 10 until the pin reaches the end of the upper guideway and engages the cam at the end thereof. The spring isk then strong enough to force the cam surface along the pin to the position shown in Fig. 11, and thereby to bring the rack into mesh With the pinion. At such time, adequate area is provided for the passage of air into the heating chamber ,during the time at which the fan is stopped. j

It will beseen from the foregoing ydescription ythat I have provided an apparatus wherein the dampers are positively moved to a closed position whenever the fan motor is started and the dampers are positively moved to an open position whenever the fanis stopped. It will also be evident that I have provided an apparatus which mayy readily be used in connection with hot air furnaces in which the air inlet conduit opens either into the furnace room or by means of risers y to one of the heated rooms. Moreover, the apparatus may readily be installed in existing types of hot air furnaces and may readily be controlled at a point remote` from the furnace room.

I claim:

1. The combination with the heating chamber of a hot air furnace, of a fan for forcing air under pressure into the chamber, means for driving the fan, a damper, means for moving the damper to open position when the fan is stopped, and disengageable rack and pinion means actuated automatically by the fan driving means for moving the damper toward closed position when the fan is started.

2. In a hot air heating furnace, the combination with a heating chamber, of a fan for forcing air under pressure into the chamber, means for driving the fan, a. damper associated with the fan, means for opening the damper automatically When the fan is stopped, a pinion actuated by the fan driving means, and a rack coacting with the pinion and operatively connected to the damper whereby the damper is closed When the fan is started, and means for moving the rack out of engagement With the pinion during the final period of damper closing movement.

3. In combination with the heating chamber of a hot air furnace having an air inlet conduit leading thereto, of a fan and a damper disposed adjacent the inlet, means for driving the fan, the fan being adapted to force air under pressure into the heating chamber, and a rack and pinion adapted to be actuated by the fan driving means for closing the damper when the fan is started, there being a cam associated with the rack, said cam functioning during movement of the rack in one direction to disconnect the rack and pinion.

4. In a hot air heating furnace, the combination With a heating chamber having an air inlet conduit leading thereto, of a fan and damper associated With the conduit, means for driving the fan, means actuated by the fan driving means for partially closing the damper when the fan is started, said damper being so mounted that air pressure in the conduit resulting from the operation of the fan will exert a final closing action on the damper.

5. In a hot air heating furnace, the combination With a heating chamber, of an air inlet conduit leading thereto, a. fan and damper associated With the conduit, means for driving the fan, there being mechanical means actuated by the fan driving means for partially closing the damper When the fan is started, the damper being finally closed by pneumatic pressure after the fan is in operation.

6. In combination, a hot air heating furnace having an air inlet conduit leading thereto, a frame disposed across the conduit and having a fan opening and a damper opening, a movable damper occupying the damper opening, a motor driven fan mounted in the fan opening, and a mechanism including a rack operatively connected to the damper and a coacting pinion operatively connected to the fan shaft for initiating the closing of the damper When the fan is started.

7. In combination, an air conduit having an opening therein, a motor driven fan occupying part of the opening, a closure member adapted to occupy another part of the opening, and means actuated by the motor and including a coacting rack and pinion for initiating the closing of the closure member When the fan is in operation, and means for opening the closure member automatically When the fan becomes inoperative.

8. In combination, a hot air heating furnace having an air inlet conduit leading thereto, a frame disposed across the conduit and having a fan opening and a plurality of damper openings, a motor driven fan occupying the fan opening and movable dampers adapted to close the damper openings, a bar having an endless guideway therein and slidably mounted on the frame and operatively connected to the dampers, a pin carried by the frame and coacting With the guide- Way, a spring acting upon the bar to cause it to open the dampers, and means associated with the motor to initiate closing movement of the dampers When the motor is started, said means being adapted to be disconnected from the motor when the dampers are closed.

In testimony whereof, I hereunto affix my signature.

JAMES C. MILES. 

